Breakaway fluid couplings are commonly employed in fluid systems wherein it is desired to disconnect fluid couplings in response to tension forces within the hose or piping associated with the couplings. For instance, breakaway couplings are commonly employed with agricultural implements wherein hydraulically operated implements are connected to tractors through impact releasable hitches whereby release of the hitch, and tensioning of the hydraulic hose, does not cause hose rupture, but permits the couplings to separate without damage to the conduit system. Examples of such apparatus are shown in the assignee's U.S. Pat. Nos. 2,463,326 and 2,705,652.
While previous breakaway fluid couplings would permit the couplings parts to separate upon predetermined axial forces being applied to the parts, prior devices are not reliable if the forces applied to the coupling parts are not substantially coaxial, and angularly misaligned forces on the parts tending to bend or pivot one part relative to the other will not permit reliable coupling separation and may result in hose rupture or damage to the coupling parts.
It is an object of the invention to provide a breakaway fluid coupling which will dependably operate under both coaxial and non-coaxial tension forces being applied to the coupling parts.
A further object of the invention is to provide a breakaway fluid coupling wherein the construction of the coupling permits limited pivotal or swivel movement between the coupling parts without damage or adversely affecting the seal therebetween, and wherein such pivoting to a predetermined extent automatically releases the coupling parts from each other.
A further object of the invention is to provide a fluid coupling having relatively pivotal interconnected parts wherein uncoupling is automatically achieved upon a predetermined pivotal displacement occurring therebetween.
Yet another object of the invention is to provide a breakaway fluid coupling having relatively pivotal parts wherein release results from either an excessive pivotal displacement between the parts occuring, or excessive tension forces are applied to the parts in a substantially coaxial direction.
In the practice of the invention the male coupling part includes a projection having an exteriorly defined spherical segment surface for establishing a sealed relationship to a spherically segmented recess defined in the female member. Additionally, the male projection includes a spherical segment locking surface concentric to the sealing surface engaged by radially movable detents mounted upon the female member. Such arrangement permits limited relative pivotal movement between the coupling parts while maintaining a sealed relationship.
The female part includes an annular locking sleeve axially slidable thereon between locking and release positions regulating the radial location of the detents. An abutment defined on the male member engages the sleeve upon a predetermined pivotal displacement occurring between the coupling parts which axially shifts the sleeve upon the female member from the locking position to the release position uncoupling the parts.
Biasing means mounted on the male member impose an equally distributed axial force on the female member tending to maintain a coaxial relationship between the coupling parts, and relative pivoting of the parts is resisted by this biasing means.
The female member also includes a conduit attachment body axially displaceable upon the female member which is spring biased in the direction opposite to that in which conduit tension forces would be applied thereto. Lost motion connection means interposed between the female conduit attachment member and the locking sleeve permit the sleeve to function as aforedescribed, and also causes the sleeve to be displaced from the locking position to the release position upon sufficient coaxial tension forces being applied to the conduit attachment means. Accordingly, the latch sleeve is automatically displaceable under dual conditions, i.e. excessive relative coupling part pivoting or excessive axial tensioning.